000 AXNT20 KNHC 211141 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU JUN 21 2012 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...SPECIAL FEATURES... TROPICAL STORM CHRIS IS CENTERED NEAR 39.9N 44.8W AT 21/0900 UTC OR ABOUT 547 NM SE OF CAPE RACE NEWFOUNDLAND MOVING E-NE AT 17 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 995 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. SCATTERED MODERATE CONVECTION IS WITHIN 45/60 NM OF THE CENTER. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. THE 1010 MB LOW HAS DISSIPATED LEAVING A SURFACE TROUGH AT 21/0900 UTC EXTENDING FROM 29N85W THROUGH THE YUCATAN CHANNEL TO 20N87W. STRONG UPPER-LEVEL WINDS OVER THE GULF OF MEXICO ARE EXPECTED TO DIMINISH IN A DAY OR SO...AND SOME GRADUAL DEVELOPMENT OF THIS SYSTEM IS POSSIBLE AS THE DISTURBANCE MOVES SLOWLY NORTHWARD TOWARD THE CENTRAL GULF OF MEXICO. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. REGARDLESS OF DEVELOPMENT...HEAVY RAINS AND LOCALIZED FLOODING ARE POSSIBLE ACROSS THE YUCATAN PENINSULA... WESTERN CUBA...AND SOUTHERN FLORIDA THROUGH SATURDAY. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER WITHIN 75 NM OF LINE FROM 22N81W TO 21N87W INCLUDING PORTIONS OF CUBA...SE GULF OF MEXICO AND NW CARIBBEAN. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE OVER THE E GULF OF MEXICO S OF 29N W OF 90W... OVER THE NW CARIBBEAN N OF 19N W OF 77W...AND PORTIONS OF THE BAHAMAS S OF 26N W OF 75W ACROSS FLORIDA AND THROUGH THE STRAITS OF FLORIDA AND WITHIN 120 NM N OF HISPANIOLA. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 13N23W TO 5N32W MOVING W NEAR 15 KT. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 250/300 NM E OF THE WAVE AXIS. TROPICAL WAVE IN THE CARIBBEAN IS NO LONGER DISCERNIBLE AND HAS BEEN DROPPED FROM THE ANALYSIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 17N16W ALONG 11N21W TO 8N26W. THE ITCZ STARTS W OF THE TROPICAL WAVE NEAR 7N33W ALONG 6N42W 7N53W TO INLAND OVER SOUTH AMERICA NEAR 6N58W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N TO INLAND OVER SW AFRICA E OF 6W TO THE PRIME MERIDIAN...FROM 4N-11N BETWEEN 12W-22W...AND FROM 5N-9N BETWEEN 33W-43W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE EXTENDS FROM AN UPPER HIGH OVER THE YUCATAN CHANNEL NW TO THE LOUISIANA/TEXAS COAST COVERING ALL BUT THE FAR NE GULF. DIFFLUENCE ALOFT TO THE W OF THE UPPER RIDGE IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS W OF 92W TO INLAND OVER MEXICO AND TEXAS. AN UPPER LOW IS INLAND OVER S ALABAMA EXTENDING AN UPPER TROUGH TO OVER THE FAR NE GULF. THE ACTIVITY OVER THE E GULF IS DESCRIBED IN THE SPECIAL FEATURES SECTION ABOVE. THE SURFACE TROUGH WILL MOVE INTO THE CENTRAL GULF AS A NEW LOW PRESSURE IS EXPECTED TO FORM OVER YUCATAN TODAY AND MOVE INTO THE S CENTRAL GULF THROUGH SAT POSSIBLY AS A TROPICAL CYCLONE. THE LOW IS THEN EXPECTED TO TRACK NE TO THE E GULF SUN AND MON. CARIBBEAN SEA... BROAD UPPER RIDGE COVERS THE CARIBBEAN ANCHORED BY AN UPPER HIGH OVER THE YUCATAN CHANNEL NEAR 22N86W WITH A RIDGE AXIS EXTENDING E TO 21N63W GIVING THE CARIBBEAN NE FLOW ALOFT. THE ACTIVITY IN THE NW CARIBBEAN IS DESCRIBED IN THE SPECIAL FEATURES ABOVE. THUNDERSTORMS THAT DEVELOPED OVER COLOMBIA CONTINUE TO MOVE INTO THE S CARIBBEAN S OF 10N E OF 79W. THIS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES THIS MORNING. A TROPICAL WAVE IN THE ATLC WILL MOVE INTO THE E CARIBBEAN SAT AND THE CENTRAL CARIBBEAN SUN. IT WILL REMAIN MOSTLY ALOFT...BUT BRING A SLIGHT INCREASE IN SHOWERS. THE ATLC RIDGE EXTENDS N OF THE AREA WILL MAINTAIN MODERATE TO FRESH TRADES ACROSS THE CARIBBEAN WITH OCCASIONALLY HIGHER WINDS ALONG THE N COAST OF SOUTH AMERICA. ATLANTIC OCEAN... A CUT OFF UPPER LOW IS CENTERED OVER THE W ATLC NEAR 29N70W WITH AN UPPER TROUGH EXTENDING SW TO 24N73W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 32N67W TO 25N74W. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE E OF THE TROUGH WITHIN 120 NM OF LINE FROM 28N64W TO 22N70W. A SURFACE RIDGE COVERS THE W AND CENTRAL ATLC WITH A 1019 MB HIGH NW OF THE SURFACE TROUGH NEAR 33N72W AND A SECOND 1019 MB HIGH SE OF THE SURFACE TROUGH NEAR 27N61W. THE UPPER RIDGE OVER THE CARIBBEAN EXTENDS AN UPPER RIDGE AXIS FROM 21N63W ENE TO BEYOND 32N35W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120 NM OF LINE FROM 27N55W TO BEYOND 32N42W. A BROAD SURFACE RIDGE CONTINUES TO DOMINATE THE REMAINDER OF THE ATLC WITH A 1020 MB HIGH OVER THE E ATLC NEAR 29N32W. THE SURFACE TROUGH WILL DRIFT NW THROUGH THU NIGHT WHILE WEAKENING. HIGH PRESSURE WILL BUILD ALONG 26N THROUGH MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW